composer/src/Composer/DependencyResolver/Pool.php

<?php

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Composer\DependencyResolver;

use Composer\Package\LinkConstraint\LinkConstraintInterface;
use Composer\Repository\RepositoryInterface;

/**
 * A package pool contains repositories that provide packages.
 *
 * @author Nils Adermann <naderman@naderman.de>
 */
class Pool
{
    protected $repositories = array();
    protected $packages = array();
    protected $packageByName = array();

    /**
     * Adds a repository and its packages to this package pool
     *
     * @param RepositoryInterface $repo A package repository
     */
    public function addRepository(RepositoryInterface $repo)
    {
        $this->repositories[] = $repo;

        foreach ($repo->getPackages() as $package) {
            $package->setId(count($this->packages) + 1);
            $this->packages[] = $package;

            foreach ($package->getNames() as $name) {
                $this->packageByName[$name][] = $package;
            }
        }
    }

    /**
    * Retrieves the package object for a given package id.
    *
    * @param int $id
    * @return PackageInterface
    */
    public function packageById($id)
    {
        return $this->packages[$id - 1];
    }

    /**
     * Searches all packages providing the given package name and match the constraint
     *
     * @param string                  $name       The package name to be searched for
     * @param LinkConstraintInterface $constraint A constraint that all returned
     *                                            packages must match or null to return all
     * @return array                              A set of packages
     */
    public function whatProvides($name, LinkConstraintInterface $constraint = null)
    {
        if (!isset($this->packageByName[$name])) {
            return array();
        }

        $candidates = $this->packageByName[$name];

        if (null === $constraint) {
            return $candidates;
        }

        $result = array();

        foreach ($candidates as $candidate) {
            if ($candidate->matches($name, $constraint)) {
                $result[] = $candidate;
            }
        }

        return $result;
    }
}